MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

Page: 231 / 860

Using ColdFusion components 231
Note: To use URL invocation, you must set the
cffunction
tag’s
access
attribute to remote.
To pass parameters to component methods using a URL, append the parameters to the URL in
standard URL query-string, name-value pair syntax; for example:
http://localhost:8500/corpQuery.cfc?method=getEmp&lastName=camden
To pass multiple parameters within a URL, use the ampersand (&) character to delimit the name-
value pairs. For example:
http://localhost:8500/
corpQuerySecure.cfc?method=getAuth&store=women&dept=shoes
Note: To ensure data security, Macromedia strongly recommends that you not pass sensitive
information over the web using URL strings. Potentially sensitive information includes all personal
user information, including passwords, addresses, telephone numbers, and so on.
If a CFC method that you access using the URL displays output directly, the user’s browser shows
the output. (You can use the
cffunction
tag
output
attribute to disable displaying output.) If
the CFC returns a result using the
cfreturn
tag, ColdFusion converts the text to HTML edit
format (with special characters replaced by their HTML escape sequences), puts it in a WDDX
packet, and includes the packet in the HTML that it returns to the client.
Invoking component methods using a form
To invoke a method using a ColdFusion or HTML form, the following must be true:
•
The
form
or
cfform
tag
action
attribute must specify the CFC filename or path.
•
The form must have an input tag (it can be a hidden input tag) with the name method and the
method name as its value.
•
The form must have an input tag for each component method parameter. The
name
attribute
of the tag must be the method parameter name and the field value is the parameter value.
•
The
cffunction
tag that defines the CFC method being invoked must specify the
access="remote"
attribute.
If the CFC method that you invoke from the form displays output directly, the user’s browser
shows the output. (You can use the
cffunction
tag
output
attribute to disable displaying
output.) If the CFC returns a result using the
cfreturn
tag, ColdFusion converts the text to
HTML edit format, puts it in a WDDX packet, and includes the packet in the HTML that it
returns to the client.
To invoke component methods using a form:
1
Create a corpFind.cfm file with the following contents:
<h2>Find People</h2>
<form action="components/corpQuery.cfc" method="post">
<p>Enter employee's last Name:</p>
<input type="Text" name="lastName">
<input type="Hidden" name="method" value="getEmp">
<input type="Submit" title="Submit Query"><br>
</form>
In the example, the
form
tag’s
action
attribute points to the
corpQuery
component. The
input
tags invoke the component method.